“Birthday Candles” on the Sun

A cluster of coronal cells seen by SDO on June 17, 2011. (NASA/SDO AIA instrument)

Make a wish! Scientists at the Naval Research Laboratory have identified new “birthday candle” structures in the Sun’s super-hot corona that may shed some light on the way its magnetic fields evolve — especially near the edges of vast, dark, wind-spewing coronal holes.

Coronal holes are regions where the Sun’s magnetic field doesn’t loop back down but rather streams outward into space. Appearing dark in images captured in ultraviolet wavelengths, these holes in the corona allow solar material to flow directly out into the solar system, in many cases doubling the normal rate of the solar wind.

Recently witnessed by NRL researchers using NASA’s SDO and STEREO solar-observing spacecraft, features called coronal cells exist at the boundaries of coronal holes and may be closely associated with their formation and behavior.

The coronal cells are plumes of magnetic activity that stream upward from the Sun, occurring in clusters. Likened to “candles on a birthday cake”, the incredibly hot (1 million K) plumes extend outwards, punching though the lower corona.